Send email from PHP and catch the autoresponses

I'm sending emails using a PHP script and class.phpmailer.php. I need to be able to 'catch' bounces and auto-responses. I'm able to catch the bounces already. I created an alias that redirects bounces to a php script, and I parse the email there. I include some information in the original email in the headers, so I can know which emails bounced.

The same logic should work for the auto-responses, I think the problem is that the email are not getting to the server. I already have a reverse DNS configured, pointing to the server IP address.

This is part of how I send an email:

            $mail = new PHPMailer();
            $mail->From = $fromAddr;
            $mail->Sender = $sender; 
            $mail->FromName = $fromName;
            $mail->AddAddress($email);
            $mai开发者_开发百科l->IsHTML(true);
            $mail->Subject = $subject; 

the I add the headers, for example:

            $mail->AddCustomHeader($mail->HeaderLine("From", $fromAddr));
            $mail->AddCustomHeader($mail->HeaderLine("Subject", $subject));

            $mail->AddCustomHeader($mail->HeaderLine("Company-State", "Florida"));
            $mail->AddCustomHeader($mail->HeaderLine("Company-Country", "USA"));

            $mail->AddCustomHeader($mail->HeaderLine("From", $fromAddr));
            $mail->AddCustomHeader($mail->HeaderLine("Reply-To", $fromAddr));

My RDNS is something like: mail2.mydomain.com. The bounces are going to "www-data". What should I add and where? something like www-data@mail2.mydomain.com?

Tks!